1. Field of the Invention
The present invention relates generally to safety devices for preventing or minimizing the potential for leaking pipe flanges of pressurized piping systems to spray leaked fluid into the environment surrounding a particular flange connection of a piping system. More particularly, the present invention concerns a pipe flange spray shield mechanism that is secured and latched about a pipe flange so that, in the event leakage of the flange should develop, the leaked fluid will not be permitted to spray into the atmosphere and into the environment near the leaking flange connection. More specifically, the present invention concerns a mechanism for securely latching a pipe flange spray shield about a pipe flange connection and locking the latch mechanism to prevent its inadvertent release and opening.
2. Description of the Prior Art
Spray shields have been used for a number of years to protect workers and equipment from the hazardous effects of pipe flange leakage as evidenced by technical information that has been published by BETEK Sicherheitstechnik GmbH and sold in stainless steel and polypropylene materials by Industrie-Anlagen-Technik, Kronberger Strasse 3A, D-63110 Rodgau/Germany under the registered trademarks “Spray Control®” and “Safe-ring®”, www.safe-ring.com. The spray shield of Industrie-Anlagen-Technik is basically wrapped around a pipe flange joint and is tightened and latched by an over-center latch mechanism. The spray shield device is lined with a pad of metal or polymer mesh material that serves to capture liquid droplets being sprayed from a leaking flange joint and to cause the droplets to coalesce to form liquid drops that in turn flow through the interstices of the mesh material and exit the spray shield in the form of drops or a stream that descends by gravity to a leakage collector.
It is known that leaking flange joints can be subjected to fluid induced forces that tend to urge the shield away from the outer circumference of the pipe flange joint so that the leakage rate can be higher than might be expected. And if the shield has become loosened, such as by the effects of temperature change the shield may have a tendency to separate from the flange. The shield can be subject to vibration by the leaking fluid to the point that the latch mechanism can be caused to release from its tightened condition about the joined flanges, thus permitting the shield to become displaced from the flange. It is desirable therefore, to provide a flange spray shield device having means for positively locking a spray shield in tightly fitting relation about a pipe flange joint to prevent the possibility of the spray shield becoming separated from the flange joint or becoming loose and resulting in ineffective and excessive fluid spray in the event of flange joint leakage.
A spray shield that has been assembled about a pipe flange joint can be struck by workers or by tools or other equipment being used by workers or can be hit by unauthorized persons, causing a conventional latch mechanism to become unlatched and resulting in separation of the spray shield mechanism from a flange joint of a pipe system. If this should occur, in the event of pipe joint leakage the typically pressurized leaked fluid will be sprayed and the resulting spray can cover a large area surrounding the leaking pipe joint. The leaking spray, especially if particularly hazardous material is being handled by the pipe system, can result in a dangerous or hazardous condition for workers and other personnel in the immediate area and can contaminate the surrounding environment, perhaps requiring significant cleanup expense. It is desirable, therefore, to provide a spray shield system that will not tend to become unlatched and separated from pipe flanges in the event of contact by other objects. And it is most important to ensure protection of workers and the environment from significant hazards in the event a flanged pipe joint should begin to leak.
At times, for various kinds of flow control equipment, it is desirable to lock a releasable latch mechanism to prevent the latch mechanism from being released. At times, lockout devices will be employed for flange spray shields to provide a means for detecting unauthorized release and opening of spray shield devices. This “lock-out” feature is often provided for security reasons to ensure against tampering when the flow control equipment or other apparatus is left unattended for a period of time. A latch mechanism can be provided with a locking feature to ensure that the latch will not be inadvertently opened in the event the equipment should be unintentionally struck by other equipment or personnel that might be conducting activities in the immediate vicinity. Accordingly, it is desired to provide a flange joint leakage spray shield system that can be present around pipe flange joints to ensure against hazardous fluid spraying in the event of joint leakage and which is provided with a latch mechanism incorporating a locking feature to permit the latch mechanism to be temporarily locked against inadvertent or unauthorized release and opening.